Current Controversies in Cardiothoracic Imaging Low-dose Computerized Tomographic Overdiagnosis of Lung Cancer is Substantial; Its Consequences are Underappreciated-Point

Lung cancer seems an ideal screening candidate because of its frequency and lethality, its well-known risk factors, and because it can often be identified at a curable stage with noninvasive procedures. The lethality of clinically diagnosed lung cancers rendered the possibility of material overdiagnosis (OD) (by means of screening) implausible in the judgment of experienced clinicians. Increased experience with lung cancer screening trials, which showed an excess of cases in screened versus control cohorts, led to broader acceptance of its existence. The magnitude of OD and the appropriate methodology for its assessment are disputed. Overdiagnosed individuals experience substantial surgical mortality and their loss of pulmonary reserve leads, in many, to a material reduction in the duration and quality of life. To estimate the scale of computerized tomographic OD, taken as the excess of screen-identified cases versus unscreened controls, we pooled the long-term findings in the 3 reporting European trials comprising 10,675 subjects. There were 263 detected lung cancers in the low-dose, computerized tomographic-screened versus 153 in controls, a 42% excess.